nix process composition

4 files changed, 78 insertions, 0 deletions

diff --git a/src/assets/markov/Makefile b/src/assets/markov/Makefile
new file mode 100644
index 0000000..4195baf
--- /dev/null
+++ b/src/assets/markov/Makefile
@@ -0,0 +1,3 @@
+bundle:
+	nix-build markov.nix -A nixBundle
+	./result/bin/nix-bundle '((import ./markov.nix) {}).entrypoint' '/bin/markov'
diff --git a/src/assets/markov/Makefile.md b/src/assets/markov/Makefile.md
new file mode 100644
index 0000000..a680113
--- /dev/null
+++ b/src/assets/markov/Makefile.md
@@ -0,0 +1,6 @@
+---
+layout: code
+include: Makefile
+lang: make
+---
+
diff --git a/src/assets/markov/markov.nix b/src/assets/markov/markov.nix
new file mode 100644
index 0000000..042ab8d
--- /dev/null
+++ b/src/assets/markov/markov.nix
@@ -0,0 +1,63 @@
+{
+    pkgs ? import (fetchTarball "https://github.com/NixOS/nixpkgs/archive/d50923ab2d308a1ddb21594ba6ae064cab65d8ae.tar.gz") {}
+}:
+
+rec {
+
+    markov = pkgs.buildGoModule {
+        pname = "markov";
+        version = "618b666484566de71f2d59114d011ff4621cf375";
+        src = pkgs.fetchFromGitHub {
+            owner = "mediocregopher";
+            repo = "markov";
+            rev = "618b666484566de71f2d59114d011ff4621cf375";
+            sha256 = "1sx9dr1q3vr3q8nyx3965x6259iyl85591vx815g1xacygv4i4fg";
+        };
+        vendorSha256 = "048wygrmv26fsnypsp6vxf89z3j0gs9f1w4i63khx7h134yxhbc6";
+    };
+
+    entrypoint = pkgs.writeScriptBin "markov" ''
+        #!${pkgs.stdenv.shell}
+
+        # On every run we create new, temporary, configuration files for redis and
+        # circus. To do this we create a new config directory.
+        markovCfgDir=$(${pkgs.coreutils}/bin/mktemp -d)
+        echo "generating configuration to $markovCfgDir"
+
+        ${pkgs.coreutils}/bin/cat >$markovCfgDir/redis.conf <<EOF
+        save ""
+        dir "''${MARKOV_DATA_DIR:-$(pwd)}"
+        appendonly yes
+        appendfilename "markov.data"
+        EOF
+
+        ${pkgs.coreutils}/bin/cat >$markovCfgDir/circus.ini <<EOF
+
+        [circus]
+
+        [watcher:markov]
+        cmd = ${markov}/bin/markov \
+            -listenAddr ''${MARKOV_LISTEN_ADDR:-localhost:8000} \
+            -timeout ''${MARKOV_TIMEOUT:-720}
+        numprocesses = 1
+
+        [watcher:redis]
+        cmd = ${pkgs.redis}/bin/redis-server $markovCfgDir/redis.conf
+        numprocesses = 1
+        EOF
+
+        exec ${pkgs.circus}/bin/circusd $markovCfgDir/circus.ini
+    '';
+
+    nixBundleSrc = pkgs.fetchFromGitHub {
+        owner = "matthewbauer";
+        repo = "nix-bundle";
+        rev = "8e396533ef8f3e8a769037476824d668409b4a74";
+        sha256 = "1lrq0990p07av42xz203w64abv2rz9xd8jrzxyvzzwj7vjj7qwyw";
+    };
+
+    nixBundle = (import "${nixBundleSrc}/release.nix") {
+        nixpkgs' = pkgs;
+    };
+}
+
diff --git a/src/assets/markov/markov.nix.md b/src/assets/markov/markov.nix.md
new file mode 100644
index 0000000..57802b4
--- /dev/null
+++ b/src/assets/markov/markov.nix.md
@@ -0,0 +1,6 @@
+---
+layout: code
+include: markov.nix
+lang: plain
+---
+